A temperature and humidity sensor is a device that can be used in a variety of projects. It can help you measure your system’s properties, get an idea about the optimal temperature for a particular environment, or just monitor how things are going.

Including the sensor is one of the most important factors to consider when building, inventing or remodeling any project. So, this article will help guide you on how to choose the right temperature and humidity sensor for your project.

Principle of a Humidity Transducer

Understanding how humidity transducers function is important, especially for industrial and medical uses.

Three different types of humidity can be measured: specific, absolute, and relative. Sensors are categorized as capacitive humidity sensors, resistive humidity sensors, and thermal conductivity humidity sensors based on the three different types of humidity that they can measure. A rise in humidity values above threshold levels can cause control systems to malfunction and deliver unsafe items.

1. Capacitive Humidity Sensor

A capacitive sensor is made of two electrodes separated by a dielectric solution. The electrical capacity of the metal oxide typically varies with the relative humidity of the atmosphere as the amount of water vapor in the atmosphere rises.

2. Resistive Humidity Sensors

Resistive sensors calculate the relative humidity by using the variation in resistivity between two electrodes. It then translates it into a modification in the electrical resistance of the humidity medium.

3. Thermal Conductivity Humidity Sensors

Absolute humidity is measured using thermal conductivity humidity sensors. In this design, two NTC thermistors are suspended with the sensor from thin wires. The thermistor’s conductivity also changes due to changes in temperature, humidity, and thermistor resistance. In essence, the dry air affects the conductivity of the insulated thermostat, while the moist air affects the conductivity of the open thermostat.

How to Choose the Right Product?

When choosing a temperature and humidity sensor, there are many things to consider that can result in a successful project and a longer product life. To make sure you choose the right temperature and humidity sensor for your application, consider the following aspects:


ü Frequency Response Characteristics

The frequency range to be measured is determined by the frequency response properties of the temperature and humidity sensor, and the monitoring conditions must not be disrupted within the permitted frequency range. Moreover, there is always some delay in the sensor response.

Given this, the sensor’s frequency response must be high, and the measurable signal’s frequency range must be broad. In other words, the frequency will be low if the sensor’s measurable signal frequency is low. 

ü Linear Range

When choosing a sensor, it is first necessary to make sure its range satisfies the specifications after determining the type of sensor. The range in which the output is directly proportional to the input is known as the temperature and humidity device’s linear range. Theoretically, the sensitivity stays constant within this range. The sensor’s range is larger and can guarantee a certain level of measurement accuracy the wider its linear range.

ü Stability

Stability is the capacity of the temperature and humidity sensor to hold constant over time. The sensor’s use environment is the most important factor influencing its long-term stability. Before choosing a sensor, you should research its suitability for the environment in which you want to manufacture the products. Then, choose the reliable sensor for that environment.


Looking for the best temperature and humidity sensor?

Get the Popular AHT20 Integrated Temperature and Humidity Sensor for Your Projects!

The AHT20 temperature and humidity sensor by Saffty has an upgraded MEMS semiconductor capacitive humidity sensor element, a standard on-chip temperature sensor element, and a newly designed ASIC dedicated chip. Temperature and humidity are automatically monitored, and the results are displayed on the LCD screen, making things easier for you. It offers excellent long-term stability with quick response and strong anti-jamming capability.

Saftty is a well-known name best recognized for developing high-quality temperature and humidity sensors and thermal protectors for use in different industries. The company strives to offer customers safe solutions with the aim of fostering a safe workplace for increased output and staff safety. Saffty products are dependable and use cutting-edge technology for the best results.


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